Unitech Smart Interlock System (SIS) is a computer-based interlocking system designed to minimize human switching errors in substations. SIS provides a real-time simulation system that accurately models the connectivity of the substation and logic of switching sequences. Through simulation, each switching step is proven safe before switching takes place. With the unified standardized lock cylinder, the operator only needs to carry one key to open all locks. By the use of RFID verification, SIS enforces the switching personnel operates on the correct equipment in sequence. Unitech was established in 1991 and has over 20,000 Smart Interlock System installations in substations, switch yards and power plants. Additional information can be found on our website of www.ut-power.com.